1. The problem statement, all variables and given/known data Counter clockwise is positive, right is positive and up is positive. My problem statement: When I use the formula ag = alfa*r do I have to take signs in to account? Or is this formula just for the magnitude and will the signs be already taken in to account in other equations? (F= m*a for example) 2. Relevant equations Ag = alfa*r (gravity point acceleration) F = m*a M = I*alfa alfa = angular acceleration 3. The attempt at a solution I am a little bit confused. In the excercise underneath I did not and I became the right solution. I think this formula gives the magnitude, the signs are already taken in account in other equations where you fill in the ag = alfa*r. Is this right? The underneath picture is as an example. Look at the highlight. My alfa is negative (angular acceleration) and my ag (aA in this case) is positive. Ag is the acceleration of the disk. IF I had taken the negative sign of the alfa in to account, that would mean that my Ag would be negative, which is not the case! Is this right? Correct me if I am wrong, thank you!